Oxidation of Si for nanostructures on silicon-on-insulator
(SOI) substrates is a key process in the fabrication of Si
single electron transistor (SET). The most di cult aspect of
the fabrication process is the formation of a nanometerscale
island sandwiched between two small capacitors
having a very thin insulator to allow electrons to pass
through in a stochastic process, known as PADOX. This
oxidation creates an island sandwiched between two
tunnel barriers which constitutes a SET. The constriction of
Si causes automatic tunnel barrier formation between
source–QD and drain-QD. The unique characteristics of
PADOX arises from i) the suppression of oxidation by
mechanical stress, and ii) the oxidation from below.